Is John Dingell in trouble?

From NBC's John YangIs Michigan Rep. John Dingell (D) -- the longest serving member of the House ever -- in trouble?

Despite the anti-incumbent political environment, Michigan's devastated economy, and the second-highest unemployment rate in the country, few thought the race would be competitive. After all, the district -- in the state's southeastern corner stretching from Ann Arbor to the Ohio border -- is so heavily Democratic that John Kerry swamped George W. Bush by 20 percentage points in 2004. And Dingell, who has not won less than 60% of the vote since 1994, has far outspent his underfunded challenger, cardiologist Robert Steele.

There's little reliable public polling in the race. But, with barely a week to go before Election Day, there are unmistakable signs of concern. One example: Former President Bill Clinton is making a hastily arranged visit to Ann Arbor on Sunday afternoon for a Dingell rally at the University of Michigan. In addition, there are signs that organized labor is shifting resources to the race as Democrats try to hang on to their House majority.

Steele, who says he was motivated to run by health-care reform, is using the slogan: "Time for a change." The seat has been held by someone named John Dingell for 77 years -- first the current congressman's father from 1933 until 1955, and then John Dingell Jr. ever since.